package com.zc.util;

import static com.zc.util.RadixUtil.hexToByte;
import static com.zc.util.RadixUtil.intHECToHex;

/**
 * @Author glb
 * @Date 2023/12/25 11:45
 * @Version 1.0
 */
public class ModbusCRC16 {

    // CRC lookup tables
    private static final int[] CRCHiTable = {
            0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,
            0x80,0x41,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
            0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,
            0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
            0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x00,0xc1,
            0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,
            0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x00,0xc1,
            0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
            0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,
            0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,
            0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,
            0x81,0x40,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
            0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,
            0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,
            0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x01,0xc0,
            0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,
            0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,
            0x80,0x41,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
            0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,
            0x80,0x41,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
            0x01,0xc0,0x80,0x41,0x00,0xc1,0x81,0x40,0x01,0xc0,
            0x80,0x41,0x00,0xc1,0x81,0x40,0x00,0xc1,0x81,0x40,
            0x01,0xc0,0x80,0x41,0x01,0xc0,0x80,0x41,0x00,0xc1,
            0x81,0x40,0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,
            0x00,0xc1,0x81,0x40,0x01,0xc0,0x80,0x41,0x01,0xc0,
            0x80,0x41,0x00,0xc1,0x81,0x40
    };

    private static final int[] CRCLoTable = {
            0x00,0xc0,0xc1,0x01,0xc3,0x03,0x02,0xc2,0xc6,0x06,
            0x07,0xc7,0x05,0xc5,0xc4,0x04,0xcc,0x0c,0x0d,0xcd,
            0x0f,0xcf,0xce,0x0e,0x0a,0xca,0xcb,0x0b,0xc9,0x09,
            0x08,0xc8,0xd8,0x18,0x19,0xd9,0x1b,0xdb,0xda,0x1a,
            0x1e,0xde,0xdf,0x1f,0xdd,0x1d,0x1c,0xdc,0x14,0xd4,
            0xd5,0x15,0xd7,0x17,0x16,0xd6,0xd2,0x12,0x13,0xd3,
            0x11,0xd1,0xd0,0x10,0xf0,0x30,0x31,0xf1,0x33,0xf3,
            0xf2,0x32,0x36,0xf6,0xf7,0x37,0xf5,0x35,0x34,0xf4,
            0x3c,0xfc,0xfd,0x3d,0xff,0x3f,0x3e,0xfe,0xfa,0x3a,
            0x3b,0xfb,0x39,0xf9,0xf8,0x38,0x28,0xe8,0xe9,0x29,
            0xeb,0x2b,0x2a,0xea,0xee,0x2e,0x2f,0xef,0x2d,0xed,
            0xec,0x2c,0xe4,0x24,0x25,0xe5,0x27,0xe7,0xe6,0x26,
            0x22,0xe2,0xe3,0x23,0xe1,0x21,0x20,0xe0,0xa0,0x60,
            0x61,0xa1,0x63,0xa3,0xa2,0x62,0x66,0xa6,0xa7,0x67,
            0xa5,0x65,0x64,0xa4,0x6c,0xac,0xad,0x6d,0xaf,0x6f,
            0x6e,0xae,0xaa,0x6a,0x6b,0xab,0x69,0xa9,0xa8,0x68,
            0x78,0xb8,0xb9,0x79,0xbb,0x7b,0x7a,0xba,0xbe,0x7e,
            0x7f,0xbf,0x7d,0xbd,0xbc,0x7c,0xb4,0x74,0x75,0xb5,
            0x77,0xb7,0xb6,0x76,0x72,0xb2,0xb3,0x73,0xb1,0x71,
            0x70,0xb0,0x50,0x90,0x91,0x51,0x93,0x53,0x52,0x92,
            0x96,0x56,0x57,0x97,0x55,0x95,0x94,0x54,0x9c,0x5c,
            0x5d,0x9d,0x5f,0x9f,0x9e,0x5e,0x5a,0x9a,0x9b,0x5b,
            0x99,0x59,0x58,0x98,0x88,0x48,0x49,0x89,0x4b,0x8b,
            0x8a,0x4a,0x4e,0x8e,0x8f,0x4f,0x8d,0x4d,0x4c,0x8c,
            0x44,0x84,0x85,0x45,0x87,0x47,0x46,0x86,0x82,0x42,
            0x43,0x83,0x41,0x81,0x80,0x40
    };

    // CRC calculation function
    public static int calculateCRC(byte[] data) {
        int byCRCHi = 0xFF;
        int byCRCLo = 0xFF;

        for (byte b : data) {
            int byIdx = (byCRCHi ^ b) & 0xFF;
            byCRCHi = (byCRCLo ^ CRCHiTable[byIdx]) & 0xFF;
            byCRCLo = CRCLoTable[byIdx] & 0xFF;
        }

        return (byCRCHi << 8) + byCRCLo;
    }

    public static void main(String[] args) {
        String nn="010300670003";
        byte[] message= hexToByte(nn);

        int crcValue = calculateCRC(message);

        //16进制结果
        System.out.println(intHECToHex(crcValue));


        // The CRC value is now ready to be split into low and high bytes
        int crcLowByte = crcValue & 0xFF;
        int crcHighByte = (crcValue >> 8) & 0xFF;
        // Output the CRC value
        System.out.printf("CRC Value: 0x%04X\n", crcValue);
        //低字节
        System.out.printf("CRC Low Byte: 0x%02X\n", crcLowByte);
        //高字节
        System.out.printf("CRC High Byte: 0x%02X\n", crcHighByte);
    }



}

